Abstract: An optical packet switching apparatus includes an optical packet switching apparatus, an optical transmitting apparatus, and an optical packet receiving apparatus. The optical packet transmitting apparatus includes a packet generator for generating a packet signal by adding the routing information to a received client signal, a BIP adding unit for adding BIP to the generated packet signal, and an electrical-to-optical converter for converting the packet signal, to which the BIP has been added, into an optical packet signal so as to be sent out. The optical packet receiving apparatus includes an electrical-to-optical converter for converting the received optical packet signal into an electrical packet signal, and a BIP comparison unit for detecting the error occurrence in the packet signal, based on the BIP added to the packet signal.

Abstract: An optical packet switching apparatus includes an optical packet switching apparatus, an optical transmitting apparatus, and an optical packet receiving apparatus. The optical packet transmitting apparatus includes a packet generator for generating a packet signal by adding the routing information to a received client signal, a BIP adding unit for adding BIP to the generated packet signal, and an electrical-to-optical converter for converting the packet signal, to which the BIP has been added, into an optical packet signal so as to be sent out. The optical packet receiving apparatus includes an electrical-to-optical converter for converting the received optical packet signal into an electrical packet signal, and a BIP comparison unit for detecting the error occurrence in the packet signal, based on the BIP added to the packet signal.

Abstract: A VOA maximum attenuation control circuit has, in addition to a conventional VOA maximum attenuation control circuit, a first resistor and a second resistor, a transistor which is an emitter follower type PNP transistor, and a capacitor. Since charge of the capacitor is 0 volt at the instant when power of the optical interface unit or each optical interface is shifted from OFF state to ON state, current is supplied to a VOA by the transistor in association with shift to the ON state of the power. As a result, attenuation of the VOA reaches maximum. When the capacitor is gradually charged, base potential of the transistor is finally +5 volts, and current is 0 ampere. Then shifting to maximum attenuation control of the VOA by an operational amplifier is realized.

Abstract: A VOA maximum attenuation control circuit has, in addition to a conventional VOA maximum attenuation control circuit, a first resistor and a second resistor, a transistor which is an emitter follower type PNP transistor, and a capacitor. Since charge of the capacitor is 0 volt at the instant when power of the optical interface unit or each optical interface is shifted from OFF state to ON state, current is supplied to a VOA by the transistor in association with shift to the ON state of the power. As a result, attenuation of the VOA reaches maximum. When the capacitor is gradually charged, base potential of the transistor is finally +5 volts, and current is 0 ampere. Then shifting to maximum attenuation control of the VOA by an operational amplifier is realized.

Abstract: A transmission apparatus has a main signal processing device, a monitor control part and an intermediating part to intermediate addresses and data between the monitor control part and the main signal processing device. The transmission apparatus further has a first switching part to selectively supply the address or the address and the data output from the intermediating part to the main signal processing device in the normal operation mode, and to selectively supply the address or the address and the data output from the monitor control part to the main signal processing device in the debug mode, and a second selecting part to selectively supply the data output from the intermediating part to the monitor control part in the normal operation mode, and to selectively supply the data output from the main signal processing device to the monitor control part in the debug mode.

Abstract: A transmission apparatus has a main signal processing device, a monitor control part and an intermediating part to intermediate addresses and data between the monitor control part and the main signal processing device. The transmission apparatus further has a first switching part to selectively supply the address or the address and the data output from the intermediating part to the main signal processing device in the normal operation mode, and to selectively supply the address or the address and the data output from the monitor control part to the main signal processing device in the debug mode, and a second selecting part to selectively supply the data output from the intermediating part to the monitor control part in the normal operation mode, and to selectively supply the data output from the main signal processing device to the monitor control part in the debug mode.